Electrical switch



y 3, 1958 G. o. BAKER ET AL 2,834,857-

ELECTRICAL SWITCH Filed Dec. 26, 1956 Fig. 5

lnvenfors George 0. Baker Francis W. Truesdell Their AHorney UnitedStates Patent ELECTRICAL swrrcn George 0. Baker, Rochester, and FrancisW. Truesdell, Dover, N. H., assignors to General Electric Company, acorporation of New York Application December 26, 1956, Serial No.630,686 2 Claims. (Cl. 200-166) This invention relates to electricalswitches and has for its objects the provision of a simple, reliable,lowcost switch having an improved arrangement for adjusting theseparation of the contacts which form a part of the switch.

The invention, together with its objects and advantages, will be readilyunderstood upon reference to the drawing annexed hereto, in which:

Figure 1 is an end view, taken in elevation, of the switch forming theinvention showing also a portion of a switch actuator together with aportion of a support plate on which the switch is mounted, and;

Figure 2 is a view from the bottom of the arrangement shown in Figure 1,and;

Figure 3 is a side view of the contact supporting block shown in Figure1, looking to the left of the drawing, and;

Figure 4 is an end view of the block shown in Figure 3, and;

Figure 5 is a view of the adjusting arm used for adjusting theseparation of the switch contacts.

Referring first to Figure 1, there is shown a pair of spaced electricalcontacts 6, 7 mounted on corresponding spaced resilient switch blades 8,9, both of which are secured to a first support member in the form ofthe molded plastic block 11, with circuit connections to the bladesbeing provided by the leads 12, 13 suitably afiixed thereto.

As is best shown in Figures 1, 2 and 3, the blades 8, 9 are mounted onopposite sides of the block 11, each blade being provided with anaperture which allows the blades to be positioned within the channels14, 15 formed in the block 11, the slightly tapered projections 16, 17extending outwardly from the center of each channel passing through theblade apertures when the blades are positioned on the block.Conventional self-locking fasteners 18, 19 may be pushed on theprojections 16, 17 to bear firmly against the blades and hold themsecurely in place.

Block 11 .has a mounting post 21 molded at one end thereof to enable theblock to be mounted on a second support member in the form of a metallicplate 22, the plate 22 having a suitable aperture through which the post21 may extend. Another self-locking fastener 23 may be pushed on thepost 21 to bear firmly against plate 22 to thus hold the block 11securely in place in plate 22.

From the above, it is seen that the switch blades may be easily andinexpensively mounted on the block 11, with the block in turn beingeasily and inexpensively mounted on the support plate 22. The block ismolded of a suitable plastic insulating material, so that it bothsupports the switch blades and insulates them from each other and fromthe mounting plate 22.

The aforesaid arrangement allows the blades 8, 9 to be mounted on block11 prior to mounting on plate 22, which has the advantage of allowingthe blades to be the switch to the on position.

2,834,857 Patented May 13, 1958 readily and easily adjusted for propercontact pressure prior to final assembly. Blade 8 is a relatively fixedblade, being only slightly biased toward blade 9 for contact wipingpurposes, whereas blade 9 is a relatively movable blade, being ratherstrongly biased toward blade 8. The biasing is such that the contactsare normally closed prior to final assembly, in which condition propercontact pressure may be obtained by bending the blades as required.

Thus far, then, there has been described a very simple, reliable andpractical arrangement of switch parts, and in order to retain thesedesirable characteristics in the overall switch combination, a simpleform of switch actuator has been provided along with a specially devisedarrangement for adjusting contact separation. The actuator is shown as apivoted member, a portion of which is shown in Figure 1 at 24, beingpivoted at 25 and including the blade engaging portion 26. The actuatoris shown biased against blade 9 to separate the contacts 6, 7i. e., theoff position of the switch is illustrated. Since the blade 9 isinitially biased toward blade 8, removal of the restraining influence ofactuator 24 will allow the blade 9 to move toward blade 8 a sufficientamount to make the contacts-i. e., change To effect this change inswitchposition, it is only necessary to move the actuator 24 in a clockwisedirection about its pivot 25 to allow the blade engaging portion 26 tomove upwardly and away from blade 9. Any suitable external means may beutilized to so move actuator 24, such as a timing motor or the like.

To adjust contact separation, the block 11 has a wedgeshaped section 27molded as a part thereof on which may be mounted the metallic adjustingarm 28, arm 28 having a notch 29 in one of its ends fitting onto saidwedgeshaped section 27. The arm 28 may thus be wedged onto block 11after which the block is mounted on plate 22 and held therein by thepush-on fasteners 23. An arcuate slot 31 is formed in arm 28, and whenthe block 11 is properly mounted in the plate 22, this slot will bealigned with an aperture 32 formed in the plate. A sheet metal screw 33,with associated lock-washer 34, is then inserted through the arcuateslot 31 and into aperture 32.

With all the parts assembled as described above, the arm 28 may then bemoved to turn the block 11 about the axis of its mounting post 21 toobtain optimum contact separation. When the block is turned, blade 8will be moved relative to blade 9 until proper separation isestablished, after which the screw 33 is driven in tightly to clamp thearm 28 to the plate 22 to hold the parts in the established position.Any further adjustment of contact spacing may be easily accomplishedsimply by loosening screw 33 and moving arm 28 as required.

Adjustment of contact separation is thus seen to be substantiallyindependent of any adjustments necessary for obtaining proper contactpressures, and the two-part design for the block 11 and its adjustingarm 28 together with the wedging relationship therebetween, allows thisindependence of adjusting action to be achieved with maximum facility atminimum costs.

Therefore, while a particular embodiment of the subject invention hasbeen shown and described herein, it is in the nature of descriptionrather than limitation, and it will occur to those skilled in the artthat various changes, modifications, and combinations may be made withinthe province of the appended claims, and without departing either inspirit or scope from this invention in its broader aspects.

What we claim as new and desire to secure by Letters Patent of theUnited States is:

l. An electrical switch comprising, in combination: first and secondspaced, resilient, relatively movable switch blades, first and secondelectrical contacts mounted on corresponding switch blades, a moldedplastic block having a wedge-shaped section molded as a part thereof anda mounting post formed on one end thereof, support means on which saidblock is mounted including a metallic plate having an opening throughwhich said mounting post extends, means for clamping said block to saidplate, said clamping means permitting limited turning of said blockabout the axis of said mounting post, means for mounting said switchblades on the other end of said block, said blades extending at rightangles to the axis of said mounting post, switch actuating means forselectively changing the spacing of said switch blades to make and breaksaid contacts, said actuating means including a member bearing againstone of said blades to normally separate said contacts, a metallicadjusting arm wedged on said block "for turning said block about theaxis of said mounting post to adjust the normal separation of saidcontacts, said adjusting arm having one end thereof notched to receivesaid wedge-shaped section whereby the two parts are wedged securelytogether, and means for clamping said adjusting arm in a fixed positionupon adjustment of said contact separation.

2. The combination defined by claim 1 wherein the other end of saidadjusting arm is provided with an arcuate slot, said support plate isprovided with an aperture aligned with said slot, and a clamping screwextends through said slot and said aperture.

References Cited in the file of this patent UNITED STATES PATENTS

